Enable Craft to build + execute from arbitary filesystem paths.

[sappenin]

Currently, Craft assumes the existence of a projects folder, and only looks for contracts to build & execute inside there. This is limiting, and should be adjusted to enable the following:

1. Craft should be able to build any WASM program (via shell commands executed in CI, or inside of the CLI itself) by specifying a file-based path.
2. Craft should be able to execute any WASM program (via shell commands executed in CI, or inside of the CLI itself) by specifying a file-based path.
3. Remove the notion of the projects folder from Craft.

[intelliot]

Working on this now

[intelliot]

• Build and execute any filesystem path #239